The challenges of an increasing mobile workforce have resulted in businesses migrating towards a more flexible and decentralized working environment These newly evolved environments have created a need for communication systems that must be capable of facilitating untethered communication at any time and any place. Consequently, there is vast growth in emerging technologies that facilitate communication anywhere and anytime. Such technologies are employed in end user devices such as pagers, cellular telephones, and mail systems such as voice mail and e-mail systems.
There presently exists both wireline telephone network systems for home and office use and cellular telephone systems for wireless mobile calls anywhere wireless services are offered (i.e., anywhere a user subscribed cellular base station reception can reach), which are interconnected to each other through the Public Switched Telephone Network (PSTN). As such, a user has a choice of contacting other telephone users or being contacted by other telephone users by using either the wireline telephone system or the cellular phone system, each having their own respective detriments.
Wireline business telephone service is typically more economical than cellular phone service. However, if a user decides to use a wireline telephone as their only business telephone they cannot be immediately contacted if they are not in their own office where their business telephone is physically located. Nor can the user easily make telephone calls while not in his own office or on travel. On the other hand, if a user decides to have a cellular phone as their only business telephone, they can be contacted at anywhere at anytime but will likely incur higher costs, e.g., airtime charges, which in total can be higher than using wireline telephone services. In the aggregate, the cost of cellular telephone service to all employees of a company is generally cost prohibitive. In addition, a cellular telephone does not typically provide the feature/function of a wireline telephone service (e.g., Integrated Services Digital Network (ISDN) and centrex feature/function).
Furthermore, if a user decides to have both a wireline telephone and a cellular phone for their business use, they incur cost for using both systems and experience the inconvenience of having two separate telephones and thus two separate voice mail systems to check for messages. A caller is also inconvenienced by having to call both the user's wireline telephone number and the user's cellular telephone to reach the user.
Wireline telephone network systems (including ISDN and centrex capabilities) and cellular telephone systems each have various feature/functions available to the user. Therefore, a need exists to provide a wireless centrex system (WCS) having features and functions presently available in existing wireline service and cellular services, as well as offering new feature/functions, while offering low cost telephone service for the working environment.
Our prior applications have disclosed a wireless centrex architecture including a Network Server Platform (NSP) and a Voice Access Port (VAP). Voice messaging and announcement services are provided from the NSP or the VAP. The Network Server Platform may serve as many as tens of thousands of subscribers while the VAP reaches in the hundreds and is physically closer to the user.